Niimbus US 5 PRO

Reference Headphone & Speaker Amplifier – with 256-step Volume Control

The Niimbus US 5 PRO is the refined successor to the acclaimed US 4 and US 4+ headphone amplifiers. Sharing the same brilliant engineering as the US 5, the PRO version adds a precise 256-step volume control using reed relays.

Premium Multi-Device

Enjoy a compact, superb-sounding headphone amplifier and a premium preamplifier in one unit. The advanced preamp section allows direct connection of power amps or active speakers. Headphone and line outputs can be switched individually from the front panel.

Remote Control

The elegant solid-aluminium remote gives infrared access to the motorised 256-step volume control, mute, input selection and headphone/line-out routing.

Technology Highlights

• Perfect volume control: 256 precise steps via reed relays.
• Lowest noise: very low internal gain keeps self-noise virtually inaudible.
• High output voltage: ±50 V internal supply – ideal for high-impedance headphones.
• High output power: ample reserves – perfect for low-impedance and magnetostatic headphones.
• High damping factor: extremely low output impedance for an uncompromisingly flat frequency response.

Features & Connections

• 3 analogue stereo inputs: 2× RCA unbalanced, 1× XLR balanced
• Pre-gain: –18 … +24 dB for perfect matching between source and headphones
• Motorised volume and manual balance control
• 4 amplifier stages: 7000 mW Pmax @50 Ω, 32 V RMS @600 Ω
• DC and overload monitoring on headphone outputs
• Headphone and line outputs selectable independently
• Headphone outs: 1× 4-pin XLR (balanced), 1× 4.4 mm Pentaconn (balanced), 2× 6.3 mm jacks (unbalanced)
• Line-out: 1× RCA (unbalanced), 1× XLR (balanced), output trim ±12 dB
• 2 toroidal transformers, > 50,000 µF filter capacity